Rock drill



March 1932- s. B CREVELING ET AL 1,849,541

ROCK DRILL Filed May 26. 1928 2 Sheets-Sheet l gwu mto'o 5. 01% Ire Z ROCK DRILL Filed May 26, 192B 2 Sheets-Sheet 6 a z T m A {A 6 a .1 i z .i M! y M m a 5. A a \t Z "9w I M Z 7 fr 5 i w. /5

gvvuenl or Zing ,ZdWfl/"d 61 randy 1205011 Patented Mar. 15, 1932 UNITED STATES PATENT OFFICE SAMUEL BOWMAN CREVELING AND EDWARD GRANDMASON, OF TBEMONT, PENNSYLVANIA ROCK DRILL AppIication filed May 26, 1928. Serial No. 280,831.

This invention relates to rock drills and more particularly to that type of rock drill ordinarily known as a jack hammer. 7

An important object of the invention is to provide in a device of this character an atseveral functions and of the extensible leg.

As is well known to those familiar with the art, most rock hammers are so constructed that they may be both rotated and longitudinally reciprocated. The air employed in rotating the drill is usually blown through the steel or bit to clear the opening which is being formed of dust. Ordinarily, separate controls are necessary, for any means for advancing the drill and the drill, thus dividing the manipulators attentions. with the result that damage to the drill or improper operation often results. A further object of the invention is to provide adevice of this character which, when attached to the drill, provides a minimum overall length for the com pleted drill structure, while at the same time, providing a maximum shift for the drill.

These and other objects we attain by the construction shown in the accompanying drawings, wherein for the purpose of illustration is shown a preferred embodiment of our invention and wherein y 7 Figure 1 is a side elevation partially in sec tion of a rock drill showing an attachment thereto constructed in accordance with our invention;

Figure 2 is a section on the line 22 of Figure 1; r

Figure 3 is a section on the line 33 of Figure 2;

Figure 4 is a section on the line 44 of Figure 2;

Figure 5 is a section on the line 55 of Figure 2;

Figure 6 is a section on the line 66 of Figure 2;

Figure 7 is a diagrammatic plan of the control valve.

Referring now more particularly to the drawings, the numeral 10 generally designates the casing of a rock drill having at one end a pair of ports 11 and 12. Air introduced through the port 11 controls rotation of the drill and cleaning of the opening formed by the drill, while air introduced through the port 12 controls reciprocation of the bit.

In accordance with our invention, we substitute for the head ordinarily employed at the end of the casing in which the ports 11 and 12 are formed, a casting 13 provided at its upper end with a tapered valve chamber 130; within which is rotatably mounted a tapered valve 14. The valve chamber 13a is provided at one end with an intake port 15 with which is connected an air supply hose 15a. The valve chamber 13a is provided at its other end with an exhaust port 15?). The casting 13 is longer than the diameter of the casing 10, and is secured to the casing by the drill head anchoring rods 10a. The casting 13 is secured to the casing 10 with its lower end extending below the casing and with the valve chamber 13a arranged at right angles to the axis of the casing.

The valve 14- at one end has a partition 16 forming a chamber 17 hereinafter referred to as the exhaust chamber of the valve, said chamber being at all times in communication with the exhaust port 15?). The remaining space of the interior of the valve is indicated at 18 and will hereinafter be termed the intake chamber which is at all times in communication with the intake port 15.

Secured between its ends to the lower end of the casting 13 is a cylinder 19 which parallels the axis of the drill and has arranged therein a piston 190;, the rod 20 of which is of relatively heavy construction and is extended through bearing guides formed at one end of the cylinder. The opposite end of the cylinder which is that end disposed toward bit end of the drill, is closed, as indicated at 21. Ducts 22 and 23 communicate with opposite ends of the cylinder and open to the valve chamber at points substantially diametrically opposed and in alignment with the exhaust chamber 17. The exhaust chamber 17 is only semi-cylindrical and the valve wall in communication with this chamber has formed therein two longitudinally spaced circumferentially extending series of ports 24- and 25. Each series of ports includes a pair of ports, one of which designated at 26, opens through the wall oi": the valve at the exhaust chamber and the other of which, designated at 27, opens through the wall of the valve at the intake chamber. These series are so circumferentially spaced that when the port 27 if one series is in communication with the end of its cooperating duct, the port 26 of the other series is aligned with and communicates with the other of the ducts. It will, therefore, be obvious that if air is introduced through the valve, this air may be, by properly positioning the valve, conducted to either end of the cylinder and the opposite end of the cylinder will, at the same time, be placed in communication with the exhaust chamber.

The wall of the intake chamber has likewise formed therein a pair of ports 28 and 29 which align with the ports 11 and 12 of the drill. The port 28 is elongated circumferentially of the valve wall so that it may be maintained in communication with the port 11 through a considerable period. The arrangement of the ports 26, 27, 28 and 29 is such that all of these ports may be disengaged from or moved out of alignment with their coacting ports 11, 12, 22 and 23, so that no operation of the drill takes place. \Vhen a drilling operation is to start and the drill has been properly positioned, air is introduced between the head 21 of the cylinder and the piston 19 and movement of the valve continued until the port 28 aligns with the port 11. At this time, the drill is rotating and delivering a blast of air through the bit. Air is being introduced to the head end of the cylinder and the opposite end thereof is in communication with the exhaust chamber so that there is no opposition to movement of the piston 19. The piston rod or extension foot 20 ac ordingly applies pressure against the support employed to force the drill toward the work. lontinued rotation of the valve will bring the port 29 into alignment with the port 12, at which time the drill is in full operation, rotating and reciprocating while delivering air to the drill and is being advanced with a steady pressure by the engagement of the extension leg 20 with the support.

The drilling operation having been completed, the rotation of the valve is reversed to cut off the supply to the drill and to deliver air through the duct 23 to the opposite end of the cylinder and placing the head end of the cylinder in communication with the atmosphere through the exhaust chamber 17. It will be obvious that under the latter circumstances, it the leg 20 has been secured to the support with which it is associated, the drill will be forcibly withdrawn from the rock.

vVhere the drill is in use as a stopper, that is to say, where it is used for making cuts where the drill extends upwardly either vertically or at an acute angle to the horizontal, a valve V in the connection to the rear end of the cylinder 19 is closed, so that escape of air from this end is prevented, and the piston may only move toward this end at a speed corresponding to the speed of leakage of air from the cylinder. This insures against any rapid movement of the piston which would leave the drill unsupported, except by the steel, so that it might become loosened and fall upon the person of an operator, injuring him.

It will be obvious that a device of this character may be very readily manufactured and will require no change in the ordinary construction of the rock drill. It will, of course, be obvious that if the ports 11 and 12 of the drill are disposed at a different location than that at which they are at present illustrated, the casting 13 must be modified to meet the requirements of the particular structure em-' ployed. In most drills, however, the construction illustrated is employed for the reason that the head end of the drill at which the operator usually takes his stand is most conveniently located for disposition of the ordinary control valve through which the air supply is delivered to these ports.

Since the construction hereinbefore set forth is capable of a certain range of change and modification without materially depart ing from the spirit of the invention, we do not limit ourselves to such specific structure except as hereinafter claimed.

We claim In a rock drill, a casing provided in one end with intake ports, a casting greater in length than the diameter of the casing and secured to said end of the casing with its lower portion extending below the casing. a valve chamber carried by the upper end of the cast ing and having its axis arranged at right angles to the axis of the casing, the valve chamber being provided in its side facing the casing with ports communicating with said ports of the casing, a cylinder secured between its en ds to the lower end of the casting and arranged parallel to the axis of the cas- 111g. a plston reciprocable in the cylinder, an

extension leg secured to the piston and extending beyond one end of the cylinder. first and second ducts communicating with the cylinder at opposite sides of the piston and communicating with opposite sides of the valve chamber, and a valve rotatable in said chamber and having an exhaust chamber and an intake chamber, said exhaust and intake chambers being each provided with a pair of circumferentially extending and longitudinally spaced ports, one port of the intake chamber communicating with said first duct and one port of the exhaust chamber communicating with said second duct in one position of the valve and the other port of the exhaust chamber communicating with said first duct and the other port of the intake chamber communicating with said second duct in another position of the valve, said intake chamber having longitudinally spaced ports of which one is elongated circumferentially of the valve and communicates with one of the casing ports when the valve is in said first position and when the valve is in a third position, and the other of these last named ports communicating with the other casing port when the valve is in said third position.

In testimony whereof we hereunto afiix our signatures.

SAMUEL BOWMAN CREVELING.

EDWARD GRANDMASON. 

